What are the other Names for this Condition? (Also known as/Synonyms)

• EMS (Eosinophilia-Myalgia Syndrome)
• L-Tryptophan Induced Eosinophilia-Myalgia Syndrome
• Severe Muscle Pain and Abnormally High Eosinophils

What is Eosinophilia-Myalgia Syndrome? (Definition/Background Information)

• Eosinophilia-Myalgia Syndrome (EMS) is a rare and unique disorder characterized by flu-like symptoms and elevated eosinophils (type of white blood cells) in blood. It is caused by the consumption of certain supplements including L-tryptophan and 5-hydroxytryptophan
• EMS was an epidemic that surfaced in the late 1980’s and early 1990’s from the use of contaminated L-tryptophan; but since then, there have been very few isolated cases of the syndrome reported worldwide. The condition was controlled through regulatory measures and drug recalls following its recognition
• Eosinophilia-Myalgia Syndrome can affect several body organs including the muscular system, gastrointestinal system, respiratory system, and cutaneous system, resulting in severe complications. EMS was commonly described among European and American Caucasian women (during the time of the outbreak)
• The signs and symptoms of Eosinophilia-Myalgia Syndrome that may be acute or chronic may include muscle pain, shortness of breath, skin rashes, hair loss, behavioral issues, and dulled cognitive function. If left untreated, EMS may lead to compromised liver function, heart-lung disease, and depression
• Often, symptomatic treatment is provided, which may involve the administration of pain medication, muscle relaxants, and corticosteroid drugs, apart from discontinuing use of the offending supplement. In a vast majority, the prognosis of Eosinophilia-Myalgia Syndrome is good; however, this also depends upon the severity of the condition

Who gets Eosinophilia-Myalgia Syndrome? (Age and Sex Distribution)

• Eosinophilia-Myalgia Syndrome has been reported in individuals ranging in age between 17-81 years
• Both males and females can be affected by EMS, but 84% of the reported cases are in females
• Of all the cases recorded during the outbreak, 97% of affected individuals were Caucasians; mostly belonging to the countries of USA, Germany, Canada, and the United Kingdom
• However, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Eosinophilia-Myalgia Syndrome? (Predisposing Factors)

Individuals, who have taken any of the following supplements/medications, may be at risk for developing Eosinophilia-Myalgia Syndrome:

• Contaminated L-tryptophan (it is the most common risk factor)
• 5-hydroxytryptophan (5-HTP)
• L-lysine
• Niacin

The above medications are taken sometimes as dietary and vitamin supplements, for weight loss, towards muscle building, and as sleeping pills.

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others. 

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Eosinophilia-Myalgia Syndrome? (Etiology)

Individuals with Eosinophilia-Myalgia Syndrome have abnormally high amounts of eosinophils (specialized type of white blood cells), causing toxic eosinophil granule proteins to be released at tissue sites, leading to tissue damage and severe muscle pain.

• EMS is believed to be caused by the ingestion of large amounts of contaminated L-tryptophan (a type of dietary supplement)
• Genetic, immunogenic, and environmental factors may play a role in individuals who develop EMS, in addition to use of contaminated L-tryptophan
• 5 hydroxytryptophan, L-lysine, and niacin supplements have also been rarely linked to the development of the syndrome

What are the Signs and Symptoms of Eosinophilia-Myalgia Syndrome?

The signs and symptoms of Eosinophilia-Myalgia Syndrome may vary from one individual to another; the onset of symptoms can be rapid. The acute symptoms, lasting 3-6 months after onset, can include:

• Shortness of breath (dyspnea)
• Muscle aches (myalgia), muscle cramps, and spasms
  • The muscle pain can become worse with time
  • Leg, back, and shoulder muscles are the most commonly affected muscle groups
  • These symptoms might be triggered by exercise
• Pain in the joints
• Cough
• Fever and fatigue
• Swelling from fluid buildup (edema)
• Numbness in hands, feet, arms, or legs
• Rashes that are itchy (pruritus)

The chronic symptoms include:

• Swelling, thickening, or hardening of the skin (eosinophilic fasciitis)
• Areas of hair loss (alopecia)
• Decreased sensation in the hands
• Increased sensation (hyperesthesia) in the back, legs, or arms
• Progressive muscle weakness
• Bladder dysfunction
• Mood or behavioral changes
• Decreased cognitive function that include:
  • Memory loss
  • Difficulty concentrating or communicating

Rarely, the chronic symptoms may include:

• Heart abnormalities
  • Inflammation of heart muscle (myocarditis)
  • Irregular heartbeats (arrhythmia) 
  • Palpitations
• Gastrointestinal problems
  • Nausea and vomiting
  • Diarrhea
  • Abdominal pain
• Muscle pain may go into remission, and then relapse
• Fatigue
• Shortness of breath

How is Eosinophilia-Myalgia Syndrome Diagnosed?

The diagnosis of Eosinophilia-Myalgia Syndrome is made following a careful examination of the patient’s medical history, extensive physical evaluation, identification of characteristic symptoms, and certain specialized blood tests looking for elevated levels of eosinophils.

A diagnosis of Eosinophilia-Myalgia Syndrome is based on fulfilling one of the two following patterns of symptoms:

Pattern 1

• Abrupt or discrete onset of illness followed by all 3 of the following set of symptoms:
  • Eosinophilia
  • Myalgia
  • Rash, edema, pulmonary involvement, or neuropathy

Pattern 2

• Presence of illness, with or without early documented episode, accompanied by one or more of the following symptoms that occur within 24 months of onset
  • Fasciitis
  • Neuropathy
  • Myalgia
  • Muscle cramps
• Any 3 or more of the following, within 6 months of onset
  • Fasciitis
  • Neuropathy
  • Myopathy
  • Eosinophilia 

Exclusions to the above include a diagnosis made while the individual has any of the following illnesses:

• Trichinosis
• Vasculitis
• Any infectious, allergic, neoplastic, connective tissue disorders, or other diseases that can help explain the symptoms

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Eosinophilia-Myalgia Syndrome?

The possible complications of Eosinophilia-Myalgia Syndrome include:

• Ascending polyneuropathy
• Cardiopulmonary disease
• Superimposed infections
• Communication difficulties
• Liver scarring
• Internal fibrosis
• Malignant fibrous histiocytoma (certain connective tissue cells begin to attack the individual’s own tissue)
• Scleroderma-like disease (connective tissue fibrosis, which can also affect other organs)
• Chronic pain, tenderness, or stiffness in muscles, tendons, and joints
• Cardiomyopathy (heart muscle disease)
• Depression
• Chronic fatigue syndrome
• Vision and dental defects
• Sleep disorders

How is Eosinophilia-Myalgia Syndrome Treated?

There is no known cure for Eosinophilia-Myalgia Syndrome, and hence, the affected individuals are treated based on the symptoms that are noted. The treatments may include:

• Immediately stopping the consumption of L-tryptophan or other causative agents is primary
• Muscle relaxants
• Corticosteroids for inflammation
• Analgesics or painkillers
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Diuretics, to induce urine production

How can Eosinophilia-Myalgia Syndrome be Prevented?

The prevention of Eosinophilia-Myalgia Syndrome may be achieved by avoiding or limiting intake of the following supplements:

• L-tryptophan
• 5-hydroxytryptophan
• L-Lysine
• Niacin

It is advised to talk to a dietician, if one is unsure about the consumption of healthy supplements.

What is the Prognosis of Eosinophilia-Myalgia Syndrome? (Outcomes/Resolutions)

• For a majority of individuals with Eosinophilia-Myalgia Syndrome, the prognosis is fairly good
• Roughly one-third of the affected individuals may need hospitalization for acute symptoms
• Only between 2-6% of cases are reported to be fatal due to organ damage and certain heart conditions

Additional and Relevant Useful Information for Eosinophilia-Myalgia Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/